The section continues to investigate pharmacological and behavioral treatments of substance abuse and interactions between these two forms of treatments. A primary objective of these studies is to eliminate drug use and decrease the probability of HIV transmission in cocaine- and/or heroin-dependent patients. Nearly all of the population studied inject drugs and are at high risk for contracting and spreading HIV infection. Two major non-pharmacological treatments of substance abuse, contingency management and cognitive/behavioral therapy, are under evaluation. Earlier research in our laboratory has shown that abstinence reinforcement contingencies are effective in producing significant periods of abstinence from cocaine and opiates in inner-city, intravenous, polydrug abusers receiving standard methadone maintenance treatment. A Cognitive/Behavioral counseling approach to substance abuse treatment developed in our laboratory is being integrated into the behavioral contingency management program to increase the duration of abstinence produced by the behavioral treatment alone by encouraging long-term changes in drug use and other HIV risk behaviors. In the past year we have extended the application of the contingency management technique to improving compliance with naltrexone maintenance treatment. Non-physically dependent opioid abusers were enrolled in an outpatient treatment research program and randomized to 3 groups who received either voucher incentives for ingesting naltrexone (Contingent Group), vouchers independent of naltrexone ingestion (NonContingent Group), or no vouchers (Control Group). The vouchers were exchangeable for goods and services. The results showed that the vouchers given contingent on naltrexone ingestion selectively increased adherence to the naltrexone administration regimen. Medically supervised withdrawal from opioids is a commonly used treatment but is usually not effective in establishing long-term abstinence. A procedure for initiating naltrexone maintenance during withdrawal treatment has been developed to provide a more effective post-withdrawal treatment that includes pharmacological treatment with opioid antagonists. Naltrexone administration initiated on Day 2 of a four-day buprenorphine regimen for heroin detoxification produced only moderate opiate withdrawal compared to a buprenorphine-only group that initiated naltrexone maintenance four days after completion of the buprenorphine regimen. Future efforts will be directed toward linking the buprenorphine-naltrexone withdrawal regimen with outpatient drug-free or naltrexone treatment enhanced with contingency management to maintain treatment compliance and abstinence and decrease HIV risk behaviors.